Method of refining polymerized rosin



Patented Aug. 17, 1948 IWETHZOD OF REFINING POLYIVIERIZED ROSIN Burt L.Hampton, Jacksonville, Fla., assignor, by mesne assignments, to TheGlidden Company, Cleveland, Ohio, a corporation of Ohio No Drawing.Application February 23,1946, Serial No. 649,774

Claims. 1

This invention relates to a process for improving or upgradingpolymerized rosin, by treating the latter with iodoform and heat.

When ordinary rosin is polymerized by known heat-treating methods in thepresence of known catalysts, the melting point is raised but the gradeof the polymerized rosin, as determined by its color, is loweredappreciably below that of the original rosin. Now it has been found thatsuch polymerized rosin of lower grade may be treated with iodoform andheat to restore it to substantially the grade of the original rosin fromwhich it was obtained, or to higher grades.

It accordingly is an object of this invention to 2 produce the optimumupgrading under the preferred conditions of time and temperature notedabove.

During the treatment with iodoform, some reaction products are formed,and it is desirable but not required that these reaction products beremoved from the reaction mass. This may be done conveniently bysparging the mass more or less vigorously with steam, carbon dioxide orother inert gas or vapor. The vigor of the sparging operation should begreatest at the higher treating temperatures, and may be very slight atthe low treating temperatures. In some instances it may be beneficial tomaintain the mass in an provide a process for upgrading polymerizedinert atmosphere, such as carbon dioxide, while rosin. it is beingheated to and cooled from the treat- In accordance with the processwhich has been ment temperature. discovered, the polymerized rosin isbrought to a In the following examples, the indicated temperature ofabout 150 C. to 220? C. and a amount of iodoform was added to the moltensmall amount of iodoform is stirred into the molmass of polymerizedrosin at temperatures ten mass. The temperature of the molten massaround 175 C.-195 0., after which the temperis then maintained orbrought otherwise to a ature of the mass was brought gradually to thepredetermined level between about 175 C. and indicated treatmenttemperature. Steam was 340 C. The mass is then held at this predeteralsointroduced during this period for sparging mined temperature for aperiod of time found to and stirring purposes and was continued throughefiect the desired increase in grade without causthe indicated timeperiod of the treatment, the ing undue losses of rosin as a result ofdecarvigor of the sparging treatment being adjusted boxylation or otherdestructive reactions. The in the manner indicated above.

Polymerized rosin I Example gf fi Temp. Time Grade M. P. A. N.

Grade M. P. A. N.

Minutes M 100 135 0.10 270- 00 N-WG 108 134 M 109 135 0.15 270-75 00 WG-M 100 135 0.20 270-75 50 we 10:; 135 M 100 135 0.30 270-75 60 we 108 133N- 115 132 0.30 275 00 WG+ 107.5 131 M 105 146 0.10 105-200 180 we 105.5143 time which i req ir varies v rsely with the From the precedingexamples it will be evident e p t of t t. a period of from about that ineach case the grade of the treated rosin two to four hours beingrequired at temperatures was raised, that the melting point was notrearound 175 C. and a period of from one to ten duced appreciably exceptin Example V, and that minutes b in ad q at t t mp ratur s ar u d 45substantially no destruction of the rosin occurred 340 C. The preferredtemperature range for as indicated by the negligible changes in acidnormal commercial operations is from about 250 number. Accordingly itwill be apparent that C. to 290 C., and at this temperature level a theoutstanding efiect of the treatment has been period of treatment of fromone-half hour to to upgrade the polymerized rosin, thereby imabout onehour is satisfactory. proving its commercial utility.

The amounts of iodoform used in the process Having now described theinvention, what is lie in the catalyst range rather than in the recla edi agent range, amounts of from about .03% t0 1. The process for refiningpolymerized rosin about 1% being efiective. For most purposes. whichcomprises the steps of: heating said rosin amounts of from about .10% to.40% are found to 55 to a temperature between about C. and 220 C.;mixing iodoform with said heated rosin in amounts of from about 03% to1% by weight of the latter; bringing the temperature of the mixture tobetween about 175 C". and 340 C. and maintaining said temperaturetherewithin for a period of time related inversely to temper ature inthe range of from 2 to 4 hours at 175 C. to about 1 to 10 minutes at 340C. to effect improvements in grade without substantial decarboxylation.

2. The process for upgrading polymerized rosin which comprises the stepof heating said poly merized rosin at temperatures between about 175 C.and 340 C. in the presence of from about 03% to 1% of iodoform as thesole catalyst for a period of from about four hours to one minute, thetime and temperature being inversely related to effect improvements ingrade without substantial decarboxylation.

3. The process for upgrading polymerized rosin which comprises the stepof heating said polymerized rosin at temperatures between about 250 C.and 290 C. in the presence of from about .10% to .40% iodoform as thesole catalyst for a period of from about one-half to one hour.

4. The process for upgrading polymerized rosin which comprises the stepsof heating said polymerized rosin at temperatures between about 175 C.and 340 C. in the presence of inert sparging gases and of from about.03% to 1% of iodoform as the sole catalyst for a period of from aboutfour hours to about one minute, the time and temperature of treatmentbeing inversely related to efiect improvements in grade with substantialdecarboxylation.

5. The process for upgrading polymerized rosin which comprises the stepof heating said polymerized rosin at temperatures between about 250 C.and 290 C. in the presence of inert sparging gases and f from about 10%to 40% of iodoform as the sole catalyst for a period of from aboutone-half to one hour.

BURT L. HAMPTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2341 341 Ender May 6, 19412,298,271 Auer Oct. 13, 1942

